What price size? When we reviewed the BMW 320d Efficient Dynamics a few weeks back we found it to be fundamentally brilliant and concluded by saying that it was all the car you could ever need. So why might you want to take a step up the BMW ladder, shell out a few grand more and plump instead for a 5-Series? A 520d Efficient Dynamics to be precise. We put one through a Pocket-lint review to find out.

The 5-Series, in its latest shape, has been on sale in the UK since 2010. But only fairly recently did BMW add this, the “Efficient Dynamics” version. It uses the 2-litre diesel engine that four out of five buyers choose - but tweaks a few things for better emissions and fuel economy.

The point, of course, is to attract company car buyers with a close eye on how much tax they pay. And given that’s linked to the CO2 emissions of the car, this version of the 5-Series makes a compelling case – emitting 119g/km, for comparison, that’s better than either a 1.6 petrol or 2-litre diesel-powered Ford Focus. It betters the regular 520d by 6 g/km, meaning it’s a percentage point lower in the benefit-in-kind tables. Boring? Yes, but important if these things affect you.

Design

Such class-leading emissions and the tax benefits that come with them are just some of the reasons you’ll see so many 5-Series ploughing up and down our motorways. It’s a handsome shape, yet a less distinctive and expressive piece of design than the (famously) "Bangled" version that went before it. For some, the departure of BMW’s flamboyant former design director, Chris Bangle, whose name became a moniker for a whole generation of very different-looking BMWs, will be a relief. The new-generation design of cars, of which this 5-Series was the first, is more sober and elegant. Yet some of us mourn the loss of the expressive design of the previous car.

Step inside and things are better. It’s here where you start to feel and see the extra money you’ve spent to upgrade beyond a 3-Series. You feel like there’s more car around you, the surfaces are fuller and feel covered in better-quality material and the seats feel plumper. You benefit from a series of detail upgrades, too – the lower part of the instrument cluster for instance, which is digital across the full width of the display – whereas on the 3-Series the digital area only extends part-way across.

The layout of the major controls - gauges, centre navigation screen, climate controls and iDrive controller, are the same as nearly every other BMW – which is to say laid out with impeccable logic and clarity – but without any design flourish.

Technology

Much of what we wrote about in our 3-Series review applies here, because fundamentally the technology architecture is very similar. The iDrive controller is a copy-paste job and none-the worse for it – falling directly into your hand if you rest your arm on the between-seat armrest and working with the same infallible logic.

Similarly, the upgraded sat nav system works intuitively – you input addresses via the rotary controller quickly and easily on the fly. The screen can be split to show the map in different forms, or map and upcoming turn-by-turn directions and the digital lower area of the dash also re-configures to show you turn-by-turn instructions. Opt for the full-colour head-up display, and alongside speed, you’ll also get turn-by-turns projected on to the road ahead, too.

What’s interesting is that, should you not choose the navigation option, you’re going to feel obviously more short-changed than you do in the 3-Series, because the basic screen (which here sits under the hood of the dashboard) then becomes smaller – leaving you with a thick, black filler space. Of course, our test car came with the upgraded navigation, so we’d struggle to comment on how much of an irritant that might be to stare at every day for the next three years.

But that nav/screen decision is just one of a bewildering array of options you ought to wade through. It’s easy to add an extra ten grand to the list price, but our test car came relatively lightly specced, so for what it’s worth we reckon the critical options you want to tick are: Media Package – Business advanced (this gets you nav, enhanced phone connectivity with a USB port and BMW online assist for £1565), DAB radio (£315), 12v power socket (penny pinching at £45), and the full black panel display (£115). We’d have recommend the comfort access system too – as it removes the annoyance of having to take a fob out of your pocket to plip the car open but then getting in and having no ignition slot to put it in. Yet because it’s bundled in a "comfort package" which includes enhanced, electrically powered seats, it works out at a rather steep £1705.

Driving

You’d think that a comparatively small, 2-litre turbo diesel engine such as this might struggle to haul along the weight of such a big car. But it’s a measure of how far engine technology has come that it never feels underpowered. True, compared to the 3-Series, you are aware that it’s pulling along a bit of extra car and that means you work it harder. Which is perhaps why we achieved only 45mpg during out time with the car, compared to 62 in the 3-Series.

Yet on the road, you always feel there’s plenty of power to overtake and what the 5-Series does brilliantly is excel both on the motorway where it’s quiet and smooth and on country roads where it’s fun and easy to chuck about. It doesn’t feel as light and as quick on its feet as the 3-Series, but for a big old bus it can be flung around with alacrity and you’ll have a fair bit more fun doing it than you might in its rivals from Audi or Mercedes. It’s not quite as good as the Jaguar XF however, although overall we think that the 2-litre diesel engine much better suits the BMW’s manner than it does the Jaguar’s.

Once again though, we feel it’s necessary to refer you to the options list - or more precisely - to consider carefully if you really need the lower emissions of this Efficient Dynamics model. Good though it is, we can’t help feel that this car would be better suited to an automatic gearbox, and that’s an option you only get on the regular 520d model. That said, it’s worth noting it also bumps up emissions, and thus tax for company car drivers. It’s a £1640 option, but one you should consider. Similarly, don’t spec your 5-Series without the £985 variable damper control because without it you don’t get the option to move between the beautifully absorbent, cushioned ride in comfort, or the sharpness and better body control of sport.

Verdict

We’ve long held up the BMW 5-Series as the sensible, default choice in this size and class of car, because it drives so well and because BMW has the technology integration and functionality so well sorted. This Efficient Dynamics version of the 5-Series does little to change that view. It drives better than most of the opposition, will fundamentally save you money compared to the opposition. If it’s your company car then it’s better to be in and use on a day-to-day than the only competitor which drivers better than it – the Jaguar XF.

Whether it’s the one to go for in the range depends on how closely you’re watching the pennies and your company car tax bill. In our opinion, the sharper looks and auto option that come available with the regular 520d in MSport trim would swing the balance in its favour, if money were no object. But that will inevitably mean paying more in company car tax, so we understand if you disagree.

In fact, the car that puts the 5-Series in the most questionable light actually comes from its own mother brand. In essence, the 5-Series does little measurably better than the 3-Series, costs more and – unless you carry four or five big people regularly – doesn’t really gain you a lot of valuable extra space.

For many people, the reason to choose 5-Series will be a symbol of having reached a certain status and position in your company; in life. And given the importance of office politics, we can fully understand those who want to say they’ve ‘made it’ with BMW’s bigger car.

But for those who don’t stress so much about such things, we’d recommend taking a long drive in this car’s baby brother – the 3-Series – and seeing how it fits you for size. You could even put some of the money you’d save towards some of the things on that frighteningly long, but ever-so-tempting options list.